Added emma code coverage generation to the build file.  ant emma test emma.merge will generate emma reports for each test, then merge them.  This is a resubmit of r5781 after verifying all remoteweb tests pass.

Patch by: jlabanca
Review by: fabbott



git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@5798 8db76d5a-ed1c-0410-87a9-c151d255dfc7